Managing Coastal Erosion And Flooding Flashcards
What are the methods against erosion?
Hard engineering
Soft engineering
What is hard engineering?
This involves building structures along the coast
What are the methods of hard engineering?
Groynes Sea walls Rip rap (rock armour) Revetments Offshore breakwater
What are groynes?
Timber or rock structures built at right angles to the coast.
What do groynes do?
Trap sediment being moved along the coast by LSD - building up the beach.
What are the advantages of groynes?
The built-up beach increases tourist potential and protects the land behind.
Groynes work with natural processes to build up the beach
Not too expensive.
What are the disadvantages of groynes?
Starve beaches further along the coast of fresh sediment, because they interrupt LSD, so there may be increased erosion
Unnatural looking and rocks groynes can be very unattractive
What are sea walls?
Made of stone or concrete at the foot of a cliff, or at the top of a beach
What do sea walls do?
Usually have a curved face to reflect waves back into the sea - reduce energy
What are the advantages of sea walls?
Effective prevention of erosion
They often have a promenade for people to walk along
What are the disadvantages of sea walls?
They reflect wave energy, rather than absorbing it
They can be intrusive and unnatural looking
They are very expensive to build and maintain
What is rip rap?
Large rocks placed at the foot of a cliff, or near the top of a beach?
What does rip rap do?
Forms a permeable barrier to the sea - breaking up the waves, but allowing some water to pass through
What are the advantages of rip rap?
It’s relatively cheap and easy to construct and maintain
It’s often fishing from, or for sunbathing by tourists.
What are the disadvantages of rip rap?
The rocks used are usually from somewhere else (e.g. granite), so they don’t fit in with the local geology and can look out of place.
It can be intrusive.
The rocks can be dangerous for people clambering over them.
